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  • - Just press play, you mean?

  • - [Voiceover] Yeah, go for it. Whoa!

  • - Now, you may have seen a Ruben's tube before. That's basically a pipe with a bunch of holes

  • in it, and you pump in a flammable gas, and light it on fire, so you basically create

  • a row of Bunsen burners. What's really cool is to play some sounds into the tube, and

  • you can actually set up standing waves. That is, there are areas, there are patterns of

  • the vibration of the air where there's a lot of vibration in some parts, and not very much

  • vibration in other parts. Now, that affects the flow rate of the gas inside that tube

  • into the atmosphere, and so it affects the height of those flames. So basically, you

  • can visualize the standing wave pattern. I'm currently in Denmark with a team of physics

  • and chemistry demonstrators who have taken this experiment to the next level. They've

  • actually created a two-dimensional Ruben's tube, a whole plane of Bunsen burners, effectively.

  • How many holes in this tube?

  • - 2,500

  • - [Voiceover] 2,500 in this Pyro Board?

  • - Yeah

  • - [Voiceover] So we're gonna see 2,500 little flames. Yeah. So, do you want to light it

  • up?

  • - Yes, I really want to light it up.

  • - [Voiceover] Why did you make this?

  • - Because, we really liked the Ruben's tube, but then we thought, ah, when you put on more

  • fire, then it always gets better. And, let’s just turn it down. And then we can just try

  • to find a standing wave. So this is below the lowest standing wave. See that? It's really

  • difficult to see

  • - [Voiceover] So what are we seeing here?

  • - It's pretty much like the standing wave on the Ruben's tube. It's just in this direction.

  • This is the lowest frequency that makes a standing wave in this pulse.

  • - [Voiceover] So this is like the fundamental.

  • - It's the fundamental.

  • - [Voiceover] Can you show me what happens when you vary the volume a little bit?

  • - Yeah.

  • - [Voiceover] Whoa! That was awesome. Okay, should we try to find another standing wave?

  • - [Sune] Yes. You can see it. You can see it. You can hear it before you can see it.

  • - [Voiceover] Whoa! It's weird. With the microphones, I can actually hear, like here, I'm in a node.

  • Then here I'm in an anti-node. Here I'm in a node.

  • - [Sune] Because you can measure the sound pressure?

  • - [Voiceover] I can hear it. Like here is very much an anti-node.

  • - [Sune] I never thought about that.

  • - [Voiceover] This is a node, and you guys can hear it.

  • - [Sune] That's true.

  • - [Voiceover] It's incredible. The flames must be coming out in the anti-nodes.

  • - The flames are coming up in the anti-nodes, yeah.

  • - [Voiceover] And you can even hear it. That’s incredible.

  • - Yeah It's nice that it can do that.

  • - [Voiceover] That is awesome.

  • - [Sune] We just learned something.

  • - [Voiceover] What happens if we try to go higher frequency?

  • - [Sune] Yeah. We have something. Oh, that's a good one.

  • - [Voiceover] That is crazy. We're right in the anti-node.

  • - [Sune] Is your ears okay?

  • - [Voiceover] Oh, God!

  • - My ears are hurting now.

  • - [Voiceover] That was painful. Why don't we try to put something more pleasing to the

  • ear through the speaker and see what happens.

  • - I think that's a good idea.

  • - [Voiceover] Let's put some music on there. You ready?

  • - Go.

  • - So, you go around Denmark showing kids all about physics?

  • - We do. That's what we do.

  • - You show them the Pyro Board?

  • - We show them the Pyro Board, and we show them a whole lot of other stuff.

  • - You guys are also on YouTube?

  • - Yep, we have a YouTube channel. You can go to this link, right here.

  • - Go check it out if you want to see more of what these guys are up to. It's awesome.

  • - [Sune] It's great.

  • - Ahoy. That is the actual Czech word for hello. I have made it to Olomouc in the Czech

  • Republic, and this is partly thanks to support from Audible.com, the leading provider of

  • audio books, with over 150,000 titles in all areas of literature, including fiction, non-fiction,

  • and periodicals. Now, today I wanted to recommend a book, which is a little bit European, and

  • it's called Galileo's Daughter by Dava Sobel. I love this book because it includes the actual

  • letters written from Galileo's daughter to him during his life, and it really reveals

  • what he must have gone through as a human being. We all know about his science, and

  • about the trials that he went through, but to see this kind of insight into his personal

  • life, I think is remarkable, so you should really check out this book, and you can download

  • it for free by going to audible.com/veritasium, or you can pick any other book of your choosing

  • for a one month free trial. So I really want to thank Audible for supporting me, and allowing

  • me to go and meet great scientists, and filmmakers, and lots of people all around the world. Also,

  • I should note that I will be hosting Michio Kaku in Brisbane and Melbourne on June 5th

  • and 6th. Links in the doobly-doo. I would love to see you there. Thank you so much for

  • watching, and I will see you somewhere else in the world. Bye.

- Just press play, you mean?

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A2 US tube node wave standing anti vibration

Pyro Board: 2D Rubens' Tube!

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    amd posted on 2016/09/30
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